Globalization and increased international trade has led to an increase in maritime traffic around the world. Governments of many countries face challenges to adequately monitor maritime activity and to protect maritime resources. For example, some studies have found that 99% of the world's ocean catch is within 200 nautical miles of shore and 30% of this catch is poached. The poaching activities have been estimated to cost billions of dollars to various countries.
In addition, maritime vessels in certain locales also face threats from piracy. The International Maritime Bureau Piracy Reporting Centre reported that 326 piracy incidents have occurred in the first 8-months of 2011. In particular 186 Incidents reported for Somalia including 23 hijackings resulting in 399 hostages and 7 deaths.
Because maritime security, particularly over international shipping lanes, is an important component of a successful global economy, government vessels such as coast guard ships or naval ships are used to promote adherence with international maritime laws and customs or to assert a country's sovereignty. Due to the vastness of the operating environment and relatively small number of government vessels, it is desirable for each government vessel to be able to monitor maritime activity over a large geographical area.
Maritime domain awareness is also important to private maritime vessels, such as commercial ships and private yachts. For example, private vessels may wish to be aware of their surrounding so as to reduce risks of accidental collisions with other vessels, stationary objects or geographical features. The private vessels may also wish to monitor other targets around the vessel to detect potential pirate or terrorist activities.
Many maritime vessels, both private and public, employ some form of maritime domain awareness system to mitigate risks of being at sea Maritime vessels typically use navigational radars that detect targets within a detection range of the radar. In addition, maritime vessels over a certain displacement or of a certain class may also have an Automatic Information System (AIS) to identify and track nearby ships having the same system installed. However, the capabilities of the maritime domain awareness systems are limited. For example, if the navigational radar is used, the detection range of the radar might be limited by the horizon. Similarly, with AIS, the communication range is limited.
Accordingly, there is a need for improved maritime domain awareness systems that provides domain awareness of a larger geographical area.